1. Technical Field
The present invention relates to an optical transmitter package structure and, more particularly, to an improved optical transmitter package structure which is applicable to wavelength-division multiplexing (WDM) and is individually detachable for replacement.
2. Description of Related Art
The processing speed and processing capacity of computers are increasing with the rapid development of technology. Limited by bandwidths and data transfer rates, the conventional telecommunication transmission techniques have had problem coping with the vast amount of information in modern society. To accelerate data transfer, fiber-optic communication systems have gradually superseded the traditional copper wire communication systems. Fiber-optic communication systems have extremely large communication bandwidths and have such advantageous features over the traditional copper wire communication systems as high data transfer rates, long transmission distances, and robustness against electromagnetic interference. In fact, fiber-optic communication has been the mainstream of wired communication since its commercialization.
The so-called optical communication technology uses light waves as the signal carrier and implements data transmission between two nodes via optical fibers. An optical communication system can be generally divided by transmission medium into an optical communication side and an electrical communication side. An optical transceiver either converts the optical signal received into an electrical signal to be processed by a chip, or converts the processed electrical signal into an optical signal to be transmitted via an optical fiber, thereby achieving the objective of communication.
A significant advancement in fiber-optic communication systems took place in the fourth-generation systems, in which the use of optical amplifiers reduces the demand for relays while wavelength-division multiplexing (WDM) increases transfer rates substantially. WDM is a technique in which at least two optical signals simultaneously transmitted in a single channel are filtered in order to carry out multiplexing and demultiplexing. Basically, WDM involves a plurality of lasers emitting laser beams of different wavelengths into a single optical fiber, and each signal is transmitted in a unique color band after data modulation.
Simply put, WDM is performed by dividing the working wavelength of an optical fiber into several channels so that more data can be transmitted through the same optical fiber. A complete WDM system includes a wavelength division multiplexer at the transmitting end and a wavelength division demultiplexer at the receiving end. Typically, an optical transmitter for use in WDM is manufactured by packaging a plurality of laser semiconductors into one module. Therefore, if any component of an optical transmitter module is damaged or found to be defective (NG) during the manufacturing process, the entire optical transmitter module must be replaced, which is obviously uneconomical.